A two-stage turbo-charger engine system is disclosed in U.S. Pat. No. 4,930,315. This turbo-charger system is limited insofar as it is difficult to provide a diesel particle filter. Normally, one would provide an oxidation catalyst close to the engine and an under floor diesel particle filter. A vehicle equipped with such an engine has an unnecessary low performance and loss of heat when the DPF is regenerated. A two-stage switchable turbocharger is also known from DE 102 30 934 A1. Each turbine has a controllable bypass which is provided with a waste-gate valve.
It is at least one object of the invention to provide a vehicle with a clean and powerful engine within current vehicle platform architectures. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary and detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.